Monoazo dyestuffs containing an amino-naphthol



United States Patent 9 3,284,436 MONQAZO DYESTUFFS (IQNTAINING ANAMIINQ-NAPHTHOL Franz Frisch, Porza, Ticino, Switzerland, assignor toFarbenfabrilren Bayer Alrtiengesellschaft, Leverlrusen, Germany, acorporation of Germany No Drawing. Filed Nov. 23, 1965, Ser. No. 50?,441Claims priority, application Switzerland, July 24, 1959, 76,170/%; June30, 1960, 7,397/60 2 Claims. (Cl. 260-498) The present application is acontinuation-in-part of copending application Serial No. 326,354, filedNovember 27, 1963, which in turn is a continuation-in-part ofapplication Serial No. 44,526, filed July 22, 1960, and now abandoned.

This invention relates to azo dyestuffs of the formula SO H (I) whereinR represents 2,4-dimethylphenyl, 3,5-dimethylphenyl, 3,6-dimethylphenylor 2,4,6-trimethylphenyl. These new dyestuffs of Formula I areconveniently prepared by coupling 1 mole of the diazo compound of anamine of the formula TIN-R (II) wherein R represents the same radicalsas in Formula I, with 1 mole of Z-amino-8-hydroxynaphthalene-6-sulfonicacid. Generally, the procedure employed is to diazotize the amine bymethods known per se, preferably indirectly in the presence of a mineralacid such as hydrochloric acid and, if necessary, with the addition ofan organic solvent such as glacial acetic acid or an alcohol. Thethus-obtained diazo compound is then coupled with theZ-amino-8-hydroxynaphthalene-6-sulfonic acid in a weakly acid mediumwith the addition of an acid-binding agent such as sodium acetate,sodium formate, sodium bicarbonate, or sodium carbonate.

The solubility and the dyeing properties of the new dyestuffs can beimproved by the addition of phosphates, e.g. sodium metaphosphate orsodium pyrophosphate and also by levelling agents.

The new dyestuffs dye animal fibers such as wool and silk, syntheticpolyamide fibers and leather in bright bluish red shades.

Dyeings of these dyes possess excellent fastness to chlorine andformaldehyde, very good carbonizing fastness and good fastnes tosea-water, chlorinated swimming pool water, chlorine carpet washing,peroxide bleaching, cross dyeing in neutral, acetic acid and sulfuricacid baths, decatizing, pressing, heat, sulfite, potting, solvents andpermutite-treated water. The dyeings are dischargeable. The dyes arehighly suitable for application by high temperature processes up to 115C. They are not sensitive to iron and copper. The dyes have highsaturation points on nylon and other polyam-ide fibers and are wellsuited for dyeing this class of fibers; they cover polyamide materialsof irregular afiinity very well, especially when applied in the presenceof a sulforicinoleate of a high degree of sulfonation. The dyes havealso very good buildingup properties on wool and synthetic polyarnidefibers and can be applied from acid, neutral or alkaline dyebaths, e.g.at pH-values from 2 to 10, but preferably from a neutral to weakly aciddyebath, e.g. at pH-values from 7 to 3 or 5 to 4 respectively. The dyeshave very good solubility in water. The dyeing on animal fibers arelevel, fast to light, perspiration, alk-alis and acids, and have verygood fastness to water, washing, rubbing, acid and alkaline milling.They are especially suitable for combination shades. Cotton, regeneratedcellulose fibers,

acetate, triacetate, acrylic and polyester fibers are completelyreserved by the dyes.

The following example is a presently preferred embodiment. Allpercentages and parts are by weight and the temperature is in degreesCentigrade, unless otherwise indicated.

28.2 parts of finely ground l-amino-4-chlorobenzene- 3-sulfonic acid-N-(2,4'-dimethylphenyl)-amide are stirred into a mixture of 50 parts ofconcentrated hydrochloric acid, 100 parts of water and 150 parts of ice,and diazotized by the slow dropwise addition of a solution of 7 parts ofsodium nitrite in 30 parts of water. The excess nitrous acid isdestroyed with 0.2 part of aminosulfonic acid and the diazo solutionfiltered. The filtrate is added to a well stirred solution of 22 partsof 2-amino-8- hydroxynaphthalene-6-sulfonic acid in 500 parts of waterand 8 parts of 50% sodium hydroxide solution. After 3 hours the couplingreaction is completed at 10-25 C. The reaction can be greatlyaccelerated by gradual addition of about 30 parts of sodium acetate. ThepH-value of the solution is in the region of 4.5. The mass is heated toC. the monoazo dyestuflf so formed is salted out, and the whole isstirred overnight at room temperature. Next day the precipitate isfiltered with suction, washed with dilute common salt solution and drieda l00 C. with vacuum. The new red wool dyestuff is a dark red powderwhich dissolves in water with a bluish red coloration and dyes wool inbright level shades of bluish red which have good fastness to light andperspiration.

When the 28.2 parts of l-arnino-4-chlorobenzene-3- sulfonicacid-N-(2,4'-dimethylphenyl)-amide in the foregoing example are replacedby the equivalent amount of one of the following amines and the aboveprocedure is used, the products are bluish red dyestuffs with verysimilar properties.

1 amino 4 chlorobenzene 3 sulfonic acid I- (3 ',5 '-dimethylphenyl)-amide, l-amino-4-chlorobenzene- 3-sulfonicacid-N-(3,6'-dimethylphenyl)'arnide or 1- amino 4 chlorobenzene 3-sulfonic acid N (2,4',6- trimethylphenyl)-amide. The dyestuffs areapplied by the following procedure.

The dyebath is constituted with 4000 parts of water, 10 parts ofanhydrous sodium sulfate and 2 parts of dyestuif. The pH value of thedye bath is neutral to weakly acid (pH 5 to 7 or 7.5). parts of wettedwool fabric is entered at 40 C. The bath is brought to the boil in 30minutes and maintained at the boil for 1 hour. Then 4 parts of glacialacetic acid are added and dyeing continued at the boil for 30 minutes.The pH-value of the dyebath is acid, e.g. a pH-value of 5.5 to 4.5.During dyeing the water lost by evaporation is continuously replaced.The red dyed wool is removed, rinsed with water and dried. It is dyed inbrilliant red shades with a very good building-up property on natural orsynthetic polyamide fibers at the cited pH-value and has excellentpenetrating power in cross-wound yarn packages and is highly suitable asan element for combination shades. The procedure can be varied bybringing the bath to the boil and first adding 2 parts of glacial aceticacid and after 15 minutes at the boil the remaining 2 parts of glacialacetic acid.

3,284,436 3 4 Formulae of representative dyestufis of the foregoing NH2Example 1 are as follows:

I 5 so OH; H0 01 N=N I HN- OH, 80311 SIC: HO HNOQH I $0311 Having thusdisclosed the invention what I claim is: on, 1. An azo dyestuflf of theformula NH; NHI

I OH! S02 HO s10: HO HN-R HN I 503K (I) $0 11 wherein E R is a memberselected from the group consisting of 2,4-dimethylphenyl,3,5-dimethylphenyl, 3,6-dimethylphenyl and 2,4,6-trimethylphenyl.

2. The azo dyestuff according to claim 1 wherein R is g2,4-dimethylphenyl.

I CH8 HO No references cited. HN SOaH CHARLES B PARKER, PrimaryExaminer.

H3 DONALD M. PAPUGA, Asisstant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,284,436 November 8, 1966 Franz Frisch In the heading to the printedspecification, lines 4 to 6, strike out "assignor to FarbenfabrikenBayer Aktiengesellschaft, Leverkusen, Germany, a corporation of Germany"read assignor to Sandoz Ltd. Ba'sle, Switzerland Signed and seaied this12th day of September 1967.

(SEAL) Attcst:

ERNEST W. SWIDER Atteefing Officer EDWARD J. BRENNER Commissioner ofPatents

1. AN AZO DYESTUFF OF THE FORMULA1-((3-(R-NH-SO2-),4-CL-PHENYL)-N=N-),2-NH2,6-(H-O3S-), 8-OH-NAPHTHALENEWHEREIN R IS A MEMBER SELECTED FROM THE GROUP CONSISTING OF2,4-DIMETHYLPHENYL, 3,5-DIMETHYLPHENYL, 3,6-DIMETHYLPHENYL AND2,4,6-TRIMETHYLPHENYL.